But in cloud chambers, etc., the interactions are so frequent that the particle approximation is quite accurate.

It's clear to me that photons are not elementary particles. I suspect that all particles that carry force, like gluons for example, have similar properties. That they are more accurately represented as fields rather than particles.

However, fermions like electrons are subject to the Pauli exclusion principle. You can overlap bosons like photons. At any point in space there may be a multitude of photons. But there can only be 2 electrons at any point in space with the same energy, one with spin up and one with spin down. This suggests that in general the particle approximation is more accurate for electrons than photons.

Remember however that all these mathematical representations are basically approximations. For example, treating the particle as a point in space is certainly an approximation. And I suspect that the fields or wave functions associated with the so-called particles are also approximate. All of physics is approximate to some extent. We do not even know how many dimensions there are in the universe. But since there seems to be more than 3 or 4, all physics that comes from the standard model is therefore approximate.